Re: [PATCH v6 2/2] optee: add per cpu asynchronous notification

On Wed, 22 Mar 2023 at 18:52, Etienne Carriere etienne.carriere@linaro.org wrote:

Implements use of per-cpu irq for optee asynchronous notification.

Existing optee async notif implementation allows OP-TEE world to raise an interrupt on which Linux optee driver will query some pending events. This change allows the signaling interrupt to be a per-cpu interrupt as with Arm GIC PPIs. Using a PPI instead of an SPI is useful when no GIC lines are provisioned in the chip design and there are spare PPI lines.

Cc: Jens Wiklander jens.wiklander@linaro.org Cc: Sumit Garg sumit.garg@linaro.org Cc: Marc Zyngier maz@kernel.org

Co-developed-by: Alexandre Torgue alexandre.torgue@foss.st.com Signed-off-by: Alexandre Torgue alexandre.torgue@foss.st.com Signed-off-by: Etienne Carriere etienne.carriere@linaro.org

---

Changes since v5:

• Removed spurious __percpu attributes reported by kernel test robot (https://lore.kernel.org/lkml/202303190039.RsU7kCIu-lkp@intel.com/).

Apart from nit below, feel free to add:

Reviewed-by: Sumit Garg sumit.garg@linaro.org

Changes since v4:

• Used cpuhp_setup_state()/cpuhp_remove_state() to enable/disable the per-cpu interrupt and let CPU hotplug also manage it.
• Added a call to destroy_workqueue() that was missing in uninit_pcpu_irq().
• Rephrased commit message.

Changes since v3:

• Fixed typo in commit message.
• Added few words in commit message about why we do this change.
• Appended a 2nd commit to the series for request DT bindings update.

Changes since v2:

• Irq and per-cpu irq no more share the primary same handler function but have a common irq_handler() helper function.
• Removed useless spinlocks.
• Wrapped lines > 80 char.

Changes since v1:

• Fixed missing __percpu attribute reported by kernel test robot.
• Rephrased commit message and added Cc tags.

---

drivers/tee/optee/optee_private.h | 24 ++++++ drivers/tee/optee/smc_abi.c | 122 +++++++++++++++++++++++++++++- 2 files changed, 142 insertions(+), 4 deletions(-)

diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 04ae58892608..6129d43dd354 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -94,11 +94,35 @@ struct optee_supp { struct completion reqs_c; };

+/*

• • struct optee_pcpu - per cpu notif private struct passed to work functions
• • @optee optee device reference
• */

+struct optee_pcpu {

•   struct optee *optee;
  

+};

+/*

• • struct optee_smc - optee smc communication struct
• • @invoke_fn handler function to invoke secure monitor
• • @memremaped_shm virtual address of memory in shared memory pool
• • @sec_caps: secure world capabilities defined by

• •                 OPTEE_SMC_SEC_CAP_* in optee_smc.h
    

• • @notif_irq interrupt used as async notification by OP-TEE or 0
• • @optee_pcpu per_cpu optee instance for per cpu work or NULL
• • @notif_pcpu_wq workqueue for per cpu aynchronous notification or NULL

s/aynchronous/asynchronous/

-Sumit

• • @notif_pcpu_work work for per cpu asynchronous notification
• • @notif_cpuhp_state CPU hotplug state assigned for pcpu interrupt management
• */

struct optee_smc { optee_invoke_fn *invoke_fn; void *memremaped_shm; u32 sec_caps; unsigned int notif_irq;

•   struct optee_pcpu __percpu *optee_pcpu;
  

•   struct workqueue_struct *notif_pcpu_wq;
  

•   struct work_struct notif_pcpu_work;
  

•   unsigned int notif_cpuhp_state;
  

};

/** diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a1c1fa1a9c28..de7ac9a46354 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -52,6 +52,23 @@ */ #define OPTEE_MIN_STATIC_POOL_ALIGN 9 /* 512 bytes aligned */

+/* SMC ABI considers at most a single TEE firmware */ +static unsigned int pcpu_irq_num;

+static int optee_cpuhp_enable_pcpu_irq(unsigned int cpu) +{

•   enable_percpu_irq(pcpu_irq_num, IRQ_TYPE_NONE);
  

•   return 0;
  

+}

+static int optee_cpuhp_disable_pcpu_irq(unsigned int cpu) +{

•   disable_percpu_irq(pcpu_irq_num);
  

•   return 0;
  

+}

/*

• 1. Convert between struct tee_param and struct optee_msg_param

@@ -991,9 +1008,8 @@ static u32 get_async_notif_value(optee_invoke_fn *invoke_fn, bool *value_valid, return res.a1; }

-static irqreturn_t notif_irq_handler(int irq, void *dev_id) +static irqreturn_t irq_handler(struct optee *optee) {

•   struct optee *optee = dev_id;
    bool do_bottom_half = false;
    bool value_valid;
    bool value_pending;
  

@@ -1016,6 +1032,13 @@ static irqreturn_t notif_irq_handler(int irq, void *dev_id) return IRQ_HANDLED; }

+static irqreturn_t notif_irq_handler(int irq, void *dev_id) +{

•   struct optee *optee = dev_id;
  

•   return irq_handler(optee);
  

+}

static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id) { struct optee *optee = dev_id; @@ -1025,7 +1048,7 @@ static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id) return IRQ_HANDLED; }

-static int optee_smc_notif_init_irq(struct optee *optee, u_int irq) +static int init_irq(struct optee *optee, u_int irq) { int rc;

@@ -1040,12 +1063,103 @@ static int optee_smc_notif_init_irq(struct optee *optee, u_int irq) return 0; }

+static irqreturn_t notif_pcpu_irq_handler(int irq, void *dev_id) +{

•   struct optee_pcpu *pcpu = dev_id;
  

•   struct optee *optee = pcpu->optee;
  

•   if (irq_handler(optee) == IRQ_WAKE_THREAD)
  

•           queue_work(optee->smc.notif_pcpu_wq,
  

•                      &optee->smc.notif_pcpu_work);
  

•   return IRQ_HANDLED;
  

+}

+static void notif_pcpu_irq_work_fn(struct work_struct *work) +{

•   struct optee_smc *optee_smc = container_of(work, struct optee_smc,
  

•                                              notif_pcpu_work);
  

•   struct optee *optee = container_of(optee_smc, struct optee, smc);
  

•   optee_smc_do_bottom_half(optee->ctx);
  

+}

+static int init_pcpu_irq(struct optee *optee, u_int irq) +{

•   struct optee_pcpu __percpu *optee_pcpu;
  

•   int cpu, rc;
  

•   optee_pcpu = alloc_percpu(struct optee_pcpu);
  

•   if (!optee_pcpu)
  

•           return -ENOMEM;
  

•   for_each_present_cpu(cpu)
  

•           per_cpu_ptr(optee_pcpu, cpu)->optee = optee;
  

•   rc = request_percpu_irq(irq, notif_pcpu_irq_handler,
  

•                           "optee_pcpu_notification", optee_pcpu);
  

•   if (rc)
  

•           goto err_free_pcpu;
  

•   INIT_WORK(&optee->smc.notif_pcpu_work, notif_pcpu_irq_work_fn);
  

•   optee->smc.notif_pcpu_wq = create_workqueue("optee_pcpu_notification");
  

•   if (!optee->smc.notif_pcpu_wq) {
  

•           rc = -EINVAL;
  

•           goto err_free_pcpu_irq;
  

•   }
  

•   optee->smc.optee_pcpu = optee_pcpu;
  

•   optee->smc.notif_irq = irq;
  

•   pcpu_irq_num = irq;
  

•   rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "optee/pcpu-notif:starting",
  

•                          optee_cpuhp_enable_pcpu_irq,
  

•                          optee_cpuhp_disable_pcpu_irq);
  

•   if (!rc)
  

•           rc = -EINVAL;
  

•   if (rc < 0)
  

•           goto err_free_pcpu_irq;
  

•   optee->smc.notif_cpuhp_state = rc;
  

•   return 0;
  

+err_free_pcpu_irq:

•   free_percpu_irq(irq, optee_pcpu);
  

+err_free_pcpu:

•   free_percpu(optee_pcpu);
  

•   return rc;
  

+}

+static int optee_smc_notif_init_irq(struct optee *optee, u_int irq) +{

•   if (irq_is_percpu_devid(irq))
  

•           return init_pcpu_irq(optee, irq);
  

•   else
  

•           return init_irq(optee, irq);
  

+}

+static void uninit_pcpu_irq(struct optee *optee) +{

•   cpuhp_remove_state(optee->smc.notif_cpuhp_state);
  

•   destroy_workqueue(optee->smc.notif_pcpu_wq);
  

•   free_percpu_irq(optee->smc.notif_irq, optee->smc.optee_pcpu);
  

•   free_percpu(optee->smc.optee_pcpu);
  

+}

static void optee_smc_notif_uninit_irq(struct optee *optee) { if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) { optee_smc_stop_async_notif(optee->ctx); if (optee->smc.notif_irq) {

•                   free_irq(optee->smc.notif_irq, optee);
  

•                   if (irq_is_percpu_devid(optee->smc.notif_irq))
  

•                           uninit_pcpu_irq(optee);
  

•                   else
  

•                           free_irq(optee->smc.notif_irq, optee);
  

•                   irq_dispose_mapping(optee->smc.notif_irq);
            }
    }
  

-- 2.25.1